Right before my grandfather died, he would ask questions like "who let the dog in here" or "why's there a dog in here?" However, no one else in the room saw it. I recently began looking it up on the Internet and saw that his experience was not unique. Have any of you had a friend or family member see this dog or perhaps even yourself?

Sadly this is common nowadays. I say sadly, because an entity or being that is black and in the form of some type of animal is usually a demon. Demons come in a wide range of diferent forms, most commonly vultures, dogs, and small animals. They hang around during death and/or near death if the afflicted had major issues with anger etc. My guess with the dog demon is this: did he possibly have loyalty issues such as lying, cheating, or betrayal? That may have something to do with it if so.

I wouldn't say he had anger issues, though he did tend to drink. Overall though, he was a normal decent human being, well liked by everyone he knew. Supposedly he was sometimes a somewhat harsh father, though that's all I could really bring up against him.

What he saw was dog or wolf more as my friend said that guides souls to the other side.. she saw it before when she accidently summoned it and once one necromancer died that spirit came and took her soul to the spirit world.. that spirit always comes to ones that died as far as i know :) its nothing bad..